We are covering a mystery and a massive search this morning. Overnight this anguished scene as family members learned that Malaysian airlines flight 370 simply vanished with 239 people on board while flying from Kuala Lumpur in Malaysia to beijing. Such devastating news and they're swarming a news conference held by airline officials. Here's what we know. The flight went off the radar in the south China sea near Vietnam and right now there's an air and sea search and rescue mission for that Boeing 777 which never sent out a distress signal which indicates whatever happened happened quickly. Yes, this is going to be a complicated search and rescue mission. There were three Americans on board including an infant and we're going to begin our coverage with ABC's bob woodruff at the airport in beijing. Bob, good morning to you. Reporter: Good morning, Dan. This is terminal three of the beijing airport where that was supposed to land early in morning. Sadly, of course, it did not. That information from the airlines has been creeping out slowly and that has been very, very frustrating to the families. In Kuala Lumpur, Malaysian airlines CEO spoke solemnly to the press. Confirmed that the flight 370 lost contact with air traffic control at 2:40 A.M. This morning. Reporter: The plane was due to into from Kuala Lumpur to beijing, China. It went off the radar somewhere off the southern tip of Vietnam. 227 passengers from 14 different countries and 12 crew members were on board the Boeing 777. Among them three Americans. One of them a child. Here at this beijing hotel room today family members gathered in tears. "I don't want to live. What is the point of me being alive" of this mother whose 40-year-old son was on board the plane. In frustration with the airlines this woman said they were only given water and bread in the room. By the time the company's officials came out to talk, hundreds of reporters had poured in crushing into each other just to get close. At one point I could barely move. The search is now happening off the coast of Vietnam covering more than 4,000 square miles. We have requested assistance first on information or wisecondly if there is a need for search and rescue, which we cannot scope. Reporter: The night has fallen here in Asia and for the search and rescue teams that, of course, is making it harder and harder for them to operate off the coast of Vietnam. Bianna. So much still unknown. Bob, our thanks to you. We are learning who was behind the controls of flight 370. An aviation veteran, he joined the company 33 years ago and has over 18,000 flying hours and now the spotlight on that Boeing 777 and David Kerley has a look at that Boeing 777 safety record. Reporter: One of the biggest mysteries this morning is how could one of the safest jetliners in the world disappear without any word from the pilots. The safety record of the Boeing 777 is one of the best in aviation. The missing aircraft is a 200 model, 11 years old. The veteran 53-year-old pilot has been with Malaysia airs for 33 years. In a statement said "We are closely monitoring reports on Malaysia flight 370. This is a wide bodied jetliner that can fly for hours on one of its two engines. It was reportedly at altitude combof 30,000 feet when it just disappeared. So where is the jet possible wreckage? Did it suffer catastrophic failure or did the pilots miss important clues about its performance. If it went down in the ocean answers will be more difficult to answer. Finding the black boxes with all that vital information becomes much more difficult. The last big jetliner to disappear like this was an air France flight which went down in 2009. It was years before the black boxes were found and the mystery of that flight was solved. A combination then of equipment failure and the pilots failing to see the problem. To have the airplane come out of the sky intact like the air flans frightly couple of years ago and over the mid-atlantic indicates a loss of flight control capability of one sort or another and deep stall on the airplane. Reporter: This morning, there are some conflicting time lines that we're hearing coming out of Malaysia on the last communication with the jetliner. When it disappeared from radar. Questions that do have to be answered. It is likely U.S. Investigators at some point from the ntsb will join their asian counterparts to trying to reveal the mystery of Malaysia flight 370. Colonel Stephen ganyard is here with us. Walk us how this could happen. There is a range of potential causes. What is in that range? There is, Dan. Any mishap usually has some key elements that are common to all mishaps. They'll be looking at things like weather, did weather play a factor as it did in the air France mishap off Brazil that David was just talking about. Was their pilot error? Was there some kind of a catastrophic failure or was there some kind of combination of all of those? In this case, also because it's so unusual for an airplane to just disappear like this, it's almost inexplicable so they'll probably broaden their range of investigation to look at terrorism. You know, you use the word rare. Most crashes happen on takeoff or landing. So for a plane to disappear in midair give us a sense how rare is that? This is so rare it is absolutely baffling and it's baffling that we don't have any better answers this long after the mishap actually occurred so lots of questions to be answered of the there's very, very little direct evidence. Very few facts to go on. Everything we're doing now is speculation. So we can't get the answers really until we find the wreckage assuming there is wreckage and assuming the plane crashed. When you don't have a mayday signal, how hard is it to find a plane in the open water? It's going to be very difficult and one reason, the same reason the air France off Brazil crash was difficult, it sounds like this aircraft was out of radar coverage. Radars only go out 200 miles and in this part of the world their coverage is spotty so they probably were not reporting at different positions along their planned flight route and weren't even in radar contact so all we know is the altitude and the air speed and the heading that they should have been on at the last point Tharpe talking to air traffic controllers. Other than that, we have no idea where they are. That said, it's fairly shallow water. It's not deep atlantic water. It's fairly shallow south China seawater and so I think we do have a good chance of hearing those pingers that the black boxes have that will allow us to go out and find the wreckage somewhere between Vietnam and Malaysia. Colonel Stephen ganyard we really appreciate your expertise on this breaking story. Bianna. Alarming to hear him use the word terrorism. Of course, our thoughts and prayers are with the family members. We're still waiting to hear news.

This transcript has been automatically generated and may not be 100% accurate.